Need help to measure and tune the latency in Linux RT

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hi,

I have an embedded system running 2.6.33 cross compiled for ARM OMAP
with 1 GHZ uni-processor system.

The application has many threads and processes (around 15 total). In
that 1 thread is time critical and must run every interval confiurable
as 2, 4 or 8 milli sec etc. There is another thread which transfers
Images to a FTP or to HMI etc, whoever requested the image.
With this image transfer enabled my critical process misses the
deadline and timesout. This critical thread is at RR priority 50. I
used a HR timer thread with RR pri 55 to wakeup the critical thread
every 1 milli sec to do the job.
If image transfer is enabled i see that real time thread misses deadlines.

All traffic is flowing on common ethernet connection. Does it affect
in any way ?

How to find out where the kernel is waiting or delaying to schedule
the critical thread even though it is at higher RR priority. How to
measure the latency ?

I am trying to use Oprofile tool, but got some error in cross
compiling. Doesn't these tools add their own latency to the original
problem ?

Any tools ? which one is better. Please provide your input on this.


Regards
Ashoka.  K
--
To unsubscribe from this list: send the line "unsubscribe linux-embedded" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Gstreamer Embedded]     [Linux MMC Devel]     [U-Boot V2]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux ARM Kernel]     [Linux OMAP]     [Linux SCSI]

  Powered by Linux